In 1782, William Herschel entered the service of his Royal Majesty, King George III of the United Kingdom.  Over the next 20 years, he, along with his brother Alexander, would build hundred of telescopes including the largest research instruments in Europe as well as create the largest catalogue of deep sky objects ever compiled.  Assisting him in this was his sister, Caroline Herschel, who would become an exceptional astronomer in her own right.

He would seek to answer questions about the Sun's motion through space, the behavior of variable stars, the nature of stellar spectra, the shape of the Milky Way galaxy and the Sun's position in it and the composition of nebulae.

In 1788, he married Mary Pitt (nee Baldwin) and, in 1792, fathered a son, John Herschel, who would go on to be the preeminent scientist of the mid-18th century; competing his father's catalogue work by extending his observations to the Southern Hemisphere and doing much to create the technology of photography as well as making significant contributions to the philosophy of science.  

John and his wife, Margaret, would have 12 children, three of whom would become scientists that would make significant contributions during their lifetimes.